Lapping tool



Patented Feb. 1, 1944 LAPPING TOOL Foster F. Hillix, Lakewood, Ohio, assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey No Drawing. Application August 15, 1942,

Serial No. 454,995

2 Claims. (Cl. 51-309) This invention relates to improvements in lapping tools and the like.

More particularly, my invention is an improvement upon that of Arch W. Harris as described in his application of even date, Serial No. 454,996, which application discloses what is known as an intermediate lap for finishing hard metal rolls and the like.

My invention comprises a modification of the lap ofthe said application to provide a finishing lap capable of producing'a highly uniform and smooth finish or polish as a final finish upon hardened steel and the like.

For this purpose, to a composition of lead and .one of the group consisting of metallic sodium, potassium or calcium, I have added mercury, whereby the resulting alloy affords an excellent lap when molded into block form for finishing operations upon hardened steel metal-working rolls and the like. The said finishing lap, like the aforesaid intermediate lap, is deliquescent, and may be used with water containing the abrasive grain for producing a final highly polished finish following the use of said intermediate lap.

My finishing" lap and composition may contain from about 1% to 3% by weight 01 the group metal with from 28% to 33% of mercury by weight, the balancebeing lead. The addition of the mercuryimparts the proper quality to the composition and tool for successful operation for the purposes stated.

As a specific example of such a "finishing lap, a composition containing about 3% metallic sodium, 33% mercury, and 64% lead may be employed with fine abrasive grain and water to produce an excellent smooth and uniform finish.

Various modifications and changes are contemplated within the scope of the following claims:

I claim:

1. A finishing lap consisting of lead containing from about 1% to 3% by weight of one of the group consisting of metallic sodium, potassium and calcium, and from 28% to 33% mercury by weight, molded into block form, characterized by possessing deliquescence when employed in the presence of water.

2. A finishing lap consisting of lead containing about 3% sodium and 33% mercury by weight, molded into block form, characterized by possessing deliquescence when employed in the presence of water.

FOSTER F. HILLIX. 

